Re: [PATCH mptcp-next v25 0/5] BPF redundant scheduler, part 2

[Mat Martineau <mathew.j.martineau@linux.intel.com>]

On Thu, 15 Dec 2022, Geliang Tang wrote:

> v25:
> - update calls to mptcp_subflow_set_scheduled(subflow, false) in
>  __mptcp_subflow_push_pending().
> - rebased on "tag: export/20221215T054923"
>

Thanks for all the work on this Geliang. I think it's ok to add this to 
the export branch for further testing, and any fixes/updates can be 
squashed if needed.

I do have feedback on one line to delete in patch 2 (see that reply). Not 
sure if Matthieu needs a squash-to patch for that or can update when 
applying.

Should this be applied after the bpf_rr patches, or earlier in the 
"features other trees" section of the export branch?

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>


- Mat

> v24:
> - rename push to keep_pushing
> - check the scheduled bit on ssk first
> - drop delegate flag
> - depends on "mptcp: use msk_owned_by_me helper"
>
> v23:
> - patch 2 and 3: clear subflow->scheduled flag on the error paths.
>
> v22:
> - update patch 2 as Mat suggested.
> - patch 4 and 5 in v21 will send later.
>
> v21:
> - address Mat's comments in v20.
> - redundant sends on retransmit code path.
>
> v20:
> - rebased on "Squash to "mptcp: refactor push_pending logic" v19"
>
> v19:
> - patch 1, use 'continue' instead of 'goto again'.
>
> v18:
> - some cleanups
> - update commit logs.
>
> v17:
> - address to Mat's comments in v16
> - rebase to export/20221108T055508.
>
> v16:
> - keep last_snd and snd_burst in struct mptcp_sock.
> - drop "mptcp: register default scheduler".
> - drop "mptcp: add scheduler wrappers", move it into "mptcp: use
> get_send wrapper" and "mptcp: use get_retrans wrapper".
> - depends on 'v2, Revert "mptcp: add get_subflow wrappers" - fix
> divide error in mptcp_subflow_get_send'
>
> v15:
> 1: "refactor push pending" v10
> 2-11: "register default scheduler" v3
>  - move last_snd and snd_burst into struct mptcp_sched_ops
> 12-19: "BPF redundant scheduler" v15
>  - split "use get_send wrapper" into two patches
> - rebase to export/20221021T061837.
>
> v14:
> - add "mptcp: refactor push_pending logic" v10 as patch 1
> - drop update_first_pending in patch 4
> - drop update_already_sent in patch 5
>
> v13:
> - deponds on "refactor push pending" v9.
> - Simply 'goto out' after invoking mptcp_subflow_delegate in patch 1.
> - All selftests (mptcp_connect.sh, mptcp_join.sh and simult_flows.sh) passed.
>
> v12:
> - fix WARN_ON_ONCE(reuse_skb) and WARN_ON_ONCE(!msk->recovery) errors
>   in kernel logs.
>
> v11:
> - address to Mat's comments in v10.
> - rebase to export/20220908T063452
>
> v10:
> - send multiple dfrags in __mptcp_push_pending().
>
> v9:
> - drop the extra *err paramenter of mptcp_sched_get_send() as Florian
>   suggested.
>
> v8:
> - update __mptcp_push_pending(), send the same data on each subflow.
> - update __mptcp_retrans, track the max sent data.
> = add a new patch.
>
> v7:
> - drop redundant flag in v6
> - drop __mptcp_subflows_push_pending in v6
> - update redundant subflows support in __mptcp_push_pending
> - update redundant subflows support in __mptcp_retrans
>
> v6:
> - Add redundant flag for struct mptcp_sched_ops.
> - add a dedicated function __mptcp_subflows_push_pending() to deal with
>   redundat subflows push pending.
>
> v5:
> - address to Paolo's comment, keep the optimization to
> mptcp_subflow_get_send() for the non eBPF case.
> - merge mptcp_sched_get_send() and __mptcp_sched_get_send() in v4 into one.
> - depends on "cleanups for bpf sched selftests".
>
> v4:
> - small cleanups in patch 1, 2.
> - add TODO in patch 3.
> - rebase patch 5 on 'cleanups for bpf sched selftests'.
>
> v3:
> - use new API.
> - fix the link failure tests issue mentioned in ("https://patchwork.kernel.org/project/mptcp/cover/cover.1653033459.git.geliang.tang@suse.com/").
>
> v2:
> - add MPTCP_SUBFLOWS_MAX limit to avoid infinite loops when the
>   scheduler always sets call_again to true.
> - track the largest copied amount.
> - deal with __mptcp_subflow_push_pending() and the retransmit loop.
> - depends on "BPF round-robin scheduler" v14.
>
> v1:
>
> Implements the redundant BPF MPTCP scheduler, which sends all packets
> redundantly on all available subflows.
>
> Geliang Tang (5):
>  mptcp: add scheduler wrappers
>  mptcp: use get_send wrapper
>  mptcp: use get_retrans wrapper
>  selftests/bpf: Add bpf_red scheduler
>  selftests/bpf: Add bpf_red test
>
> net/mptcp/protocol.c                          | 187 +++++++++++-------
> net/mptcp/protocol.h                          |   4 +
> net/mptcp/sched.c                             |  69 +++++++
> .../testing/selftests/bpf/prog_tests/mptcp.c  |  34 ++++
> .../selftests/bpf/progs/mptcp_bpf_red.c       |  45 +++++
> 5 files changed, 264 insertions(+), 75 deletions(-)
> create mode 100644 tools/testing/selftests/bpf/progs/mptcp_bpf_red.c
>
> -- 
> 2.35.3
>
>
>

--
Mat Martineau
Intel